1. Field of the Invention
This invention relates to a sheet processing apparatus and an image forming apparatus having the sheet processing apparatus and, more particularly, to a sheet processing apparatus avoiding occurrence of clamping wires for a staple holder and an image forming apparatus having the sheet processing apparatus.
2. Description of Related Art
Image forming apparatuses such as printers may conventionally have a sheet processing apparatus in which plural sheets on which images are formed or printed are subject to a processing such as stapling upon aligning each end properly to perform such a processing on the sheets to be delivered. As such a sheet processing apparatus, a known type disposed on a side surface on a sheet delivery outlet of an image forming apparatus, has a structure that sheets printed in the image forming apparatus are fed sheet by sheet from the delivery outlet and aligned at the each end to deliver the sheets upon processing.
A stapling mechanism section is generally disposed inside the housing of the sheet postprocessing apparatus. A widely known type has a structure that a housing lid is opened to handle paper jamming at the stapling mechanism section in the apparatus interior, to replace staples, and to replace the staple mechanism section, at times of occurrences of paper jamming at the stapling section, replacements of stapling, and malfunctions of the stapling mechanism section.
With these sheet processing apparatuses having such a stapling function, however, users have to laboriously open the housing lid to handle paper jamming or staple replacement through the stapling mechanism section located at the interior of the apparatus when paper jamming occurs or staple replacement is required at the staple section because the staple mechanism section is disposed at the inner side of the housing of the sheet processing apparatus. The users therefore have to go through a large number of actions during handling of paper jamming or staple replacement, and are subject to bad maneuverability as processing on the internal apparatus located inside the housing. These apparatuses also have disadvantages such that the apparatuses become structurally complicated as the apparatus housing is formed with the lid and thereby increase the costs.
A structure has been recently devised in which users can handle unit replacement properly during paper jamming processing, staple replacement or malfunction of the stapling section upon moving the unit directly in the accessing direction, where a housing of a unit of the staple mechanism section also serves as the outer housing of the sheet processing apparatus, and where the unit is movable and detachable from the sheet processing apparatus.
With such a structure, however, the staple unit or stapler requires a detachable connector cable where the power source of the stapler is supplied from the side of the sheet processing apparatus. The connector cable is prepared to have a longer length than the necessary length in consideration of handling easiness, but the cable may be clamped between the housing of the staple holder and the apparatus body when the staple holder is moved, attached or detached, or namely, so-called xe2x80x9cwire clampingxe2x80x9d may occur.
It is an object of the invention to prevent lime clamping of the cable for a staple holder. To accomplish the above object, a representative structure of the invention is of a sheet processing apparatus having a stapling means disposed detachably for stapling to conveyed sheets. The stapling means takes an operation position for stapling processing to a conveyed sheet and a replacement position for detaching the stapling means from the apparatus. The stapling means includes a connection portion connected to the apparatus for receiving a control signal from the apparatus, a cable for transmitting the control signal from the connection portion to the stapling means, and an urging means for urging the cable toward the inner side of the stapling means.
With this invention, thus, the stapling means has the urging means for urging the cable toward the inner side of the stapling means, and therefore, the cable of the stapling means is pulled inside the stapling means, so that wire clamping in which the cable is clamped between the stapling means and the apparatus is avoided.